Effect of Coffee Intake on Oxidative Stress in Periodontal Tissues

Objectives: Oxidative stress increases with aging. Increase of oxidative stress is associated with deterioration of periodontal tissue. Therefore, it is possible that ingestion of antioxidants suppresses the increase of oxidative stress and prevent deterioration of periodontal tissue due to aging. In this study, we aimed to examine the effect of coffee intake, an antioxidants, on the increase of oxidative stress in periodontal tissue with aging.
Methods: Male Fischer 344 rats (n=25, 8 weeks old) were divided into 3 groups: 0.63% coffee diet (Group A, n = 8), 1.36% coffee diet (Group B, n = 9), and normal diet (Group C, n = 8). All rats fed the assigned diets for 12 weeks. Serum levels of reactive oxygen metabolites (ROM) and OXY adsorbent were measured as indicators of systemic oxidative stress and antioxidant ability, respectively. The level of 8-hydroxydeoxyguanosine (8-OHdG) was determined to evaluate oxidative stress in the periodontal tissue. Fluorescence staining was also performed to confirm nuclear factor erythroid 2-related factor 2 (Nrf2) translocation to the nucleus.
Results: There were no significant differences in serum ROM level among the three groups. The level of OXY adsorbent was significantly higher in the Group A and the Group B than that in the Group C (P <0.05). The number of 8-OHdG positive cells in the periodontal tissue was significantly lower in the Group B than that in the Group C (P <0.05). The number of nuclear Nrf2 in the periodontal tissue was significantly higher in the Group B than that in the Group C (P <0.05).
Conclusions: Intake of coffee could inhibit the increase in oxidative stress in periodontal tissues with aging through activating Nrf2/antioxidant defense pathway.